Glioblastoma (GBM) represents the most frequent and lethal cancer affecting the central nervous system for which no cure is currently available. The presence of Glioma Stem Cells (GSCs) has been proposed to be at the root of therapeutic failures due to their intrinsic abilities of escaping common treatments and relapsing the pathology. Thus, advances in therapeutic options may derive from the manipulation of mechanisms controlling the GSCs self-renewal, survival and functions. RE1-Silencing Transcription Factor (REST) is a master repressor of neuronal developmental programme in non-neuronal lineages, recently described as a main actor in the maintenance of the GSCs’ tumorigenic competence as its knockdown strongly impairs GSCs stemness both in vitro and in vivo. However, REST is critical for restraining neuronal cellular identity in various tissues, so that a targeted therapy to this transcriptional repressor is likely to present numerous side effects. Here, by taking advantage of a Tet-on system for the manipulation of REST expression in both human GSCs and Neural Stem Cell lines (hNSCs), we performed a transcriptomic profiling analysis in order to identify novel tumour-specific REST-regulated functions and molecular targets. Our analyses confirmed the previously reported roles of REST in neural tissues and enlightened novel REST functions in hGSCs, including the regulation of alternative hGSCs identity/state. Finally, analysis of hGSC-specific REST-regulated genes in GBM patients’ dataset revealed an inverse correlation with glioma aggressiveness, thus establishing a hGSC REST score that might provide a useful prognostic tool.

Medulloblastoma (MB) is the most common pediatric brain tumor with high morbidity and mortality. Among the four major MB groups, patients with Group3 MB currently have the worst outcome and nearly 50% are metastatic at the time of diagnosis. However, the molecular mechanisms underlying Group 3 MB are still unknown. Exploiting in vivo transfection of mouse cerebellar cells, we tested different patient- specific combinations of genes for their ability to induce Group 3 MB in mice. We identified Otx2 and cMYC as strong inducers of tumors faithfully recapitulating human Group 3 MB. To identify a druggable signaling pathway, we analyzed sequencing data of human patients harboring Otx2/cMYC overexpression. Among all the putative oncosuppressors, SMARCA4 is the most frequently mutated. Indeed, co-expression of SMARCA4 with Otx2 and cMYC is able to block tumorigenesis, through regulation of CDKN2B and CRABP1 expression. Interestingly, patient-specific SMARCA4T910M mutant is able to block wild- type SMARCA4 effects in a dominant-negative manner. Since SMARCA4 has an antagonistic relationship with histone methyltransferase EZH2, we used EZH2-inhibitors to recapitulate SMARCA4 antitumorigenic effects. Little is known about Group 3 MB developmental origin and several embryonic mouse cerebellar progenitors have been proposed as possible cell of origin. Here, we found that in postnatal mouse cerebellum, the S100b+ cells are competent to induce medulloblastoma while Math1, Sox2 and Ascl1 positive cells seem to be unresponsive to oncogenic insults. Taken together, our data suggest that the competency of different cells to develop MB could change during brain development, depending on their developmental stage and cellular identity.

Increasing evidence demonstrated that mutations altering the activity of chromatin-modifying complexes significantly contribute to liver tumour formation and progression. Inactivating mutations of members of the polycomb complexes have been found in a subset of aggressive HCCs, mainly affecting women, and in more than 20% of CCA. To clarify the role of these chromatin-associated complexes in liver homeostasis, we used a comprehensive approach taking advantage of advanced genomics approaches, histological and histochemical techniques and novel in vivo models. Our data suggest that unbalancing Polycomb activities compromises liver homeostasis, favouring tumour formation.

Esta tese pretende analisar as estratégias de aquisição ou de preservação de poder adoptadas pela Nobreza, durante o reinado de D. Dinis (1279-1325), ou seja, num período muito significativo para a afirmação do poder régio, o qual, necessariamente, passava pelo controle e diminuição dos poderes senhoriais. Partindo da reconstituição genealógica de uma centena de linhagens, o Autor pretendeu, depois, caracterizar a Nobreza do período dionisino, através da análise de três vectores essenciais, cuja articulação permitiu àquela, em grande medida, estruturar o seu poder: em primeiro lugar, o património, sobretudo em termos da sua mobilidade geográfica; em segundo lugar, o grau de ligação dessas linhagens aos meios cortesãos, no sentido de avaliar a importância das relações entre a Coroa e a Nobreza; em terceiro lugar, por fim, as alianças matrimoniais, tentando detectar qual o regime de matrimónio preferencial. Finalmente o autor tentou definir o enquadramento desta Nobreza, face a determinados contextos, tais como o demográfico, o geográfico e o político. Apercebidos, desta forma, os principais traços do quadro evolutivo da Nobreza, desde o início do século XII até aos meados do século XIV, analisou então as diferentes estratégias utilizadas pela Nobreza, dividida em dois grandes grupos - nobreza de corte e nobreza regional - durante o reinado de D. Dinis, em função do património, das relações com a Corte régia, e das alianças matrimoniais.

In the past two decades the work of a growing portion of researchers in robotics focused on a particular group of machines, belonging to the family of parallel manipulators: the cable robots. Although these robots share several theoretical elements with the better known parallel robots, they still present completely (or partly) unsolved issues. In particular, the study of their kinematic, already a difficult subject for conventional parallel manipulators, is further complicated by the non-linear nature of cables, which can exert only efforts of pure traction. The work presented in this thesis therefore focuses on the study of the kinematics of these robots and on the development of numerical techniques able to address some of the problems related to it. Most of the work is focused on the development of an interval-analysis based procedure for the solution of the direct geometric problem of a generic cable manipulator. This technique, as well as allowing for a rapid solution of the problem, also guarantees the results obtained against rounding and elimination errors and can take into account any uncertainties in the model of the problem. The developed code has been tested with the help of a small manipulator whose realization is described in this dissertation together with the auxiliary work done during its design and simulation phases. / Negli ultimi decenni il lavoro di una parte sempre maggiore di ricercatori che si occupano di robotica si è concentrato su un particolare gruppo di robot appartenenti alla famiglia dei manipolatori paralleli: i robot a cavi. Nonostante i numerosi studi al riguardo, questi robot presentano ancora oggi numerose problematiche del tutto (o in parte) irrisolte. Lo studio della loro cinematica nello specifico, già complesso per i manipolatori paralleli tradizionali, è ulteriormente complicato dalla natura non lineare dei cavi, i quali possono esercitare sforzi di sola trazione. Il lavoro presentato in questa tesi si concentra dunque sullo studio della cinematica dei robot a cavi e sulla messa a punto di tecniche numeriche in grado di affrontare parte delle problematiche ad essa legate. La maggior parte del lavoro è incentrata sullo sviluppo di una procedura per la soluzione del problema geometrico diretto di un generico manipolatore a cavi basata sull'analisi per intervalli. Questa tecnica di analisi numeirica, oltre a consentire una rapida soluzione del problema, permette di garantire i risultati ottenuti in caso di errori di cancellazione e arrotondamento e consente di considerare eventuali incertezze presenti nel modello del problema. Il codice sviluppato è stato testato attraverso un piccolo prototipo di manipolatore a cavi la cui realizzazione, avvenuta durante il percorso di dottrato, è descritta all'interno dell'elaborato unitamente al lavoro collaterale svolto durante la fase di progettazione e simulazione. / Pendant les dernières décennies, le travail d'une partie toujours croissante de chercheurs qui s'occupent de robotique s'est focalisé sur un groupe spécifique de robots qui fait partie de la famille des manipulateurs parallèles: les robots à câbles. Malgré les nombreux études que l'on a consacré à ce sujet, ces robots présentent encore aujourd'hui plusieurs problématiques complètement ou partiellement irrésolues. En particulier l'étude de leur cinématique, qui se révèle déjà complexe pour les manipulateurs parallèles traditionnels, est rendu encore plus compliqué par la nature non linéaire des câbles qui peuvent seulement exercer des efforts de traction. Le travail présenté dans ma thèse concentre donc son attention sur l'étude de la cinématique des robots à câbles et sur la mise au point de techniques numériques capables d'aborder une partie des problématiques liées à cela. La plupart du travail se concentre sur l'élaboration d'un algorithme pour la résolution du problème géométrique direct d'un manipulateur à câbles général qui se fonde sur l'analyse par intervalles. Cette technique d'analyse permet non seulement de résoudre rapidement le problème mais également de garantir les résultats obtenus en cas d'erreur de cancellation et d'arrondi et de prendre en considération les incertitudes éventuellement presentes dans le modèle du problème. Le code développé a été testé grâce à un petit prototype de manipulateur à câbles dont la réalisation, qui a eu lieu pendant le parcours de doctorat, est décrite à l'intérieur du devoir en accord avec la phase de conception du projet et de simulation.

Recently, a prototype of a hand exoskeleton for post-stroke rehabilitation purpose was proposed by the Group of Robotics, Automation and Articular Biomechanics (GRAB) at the Department of Industrial Engineering, University of Bologna. The prototype comprises five planar mechanisms (one per finger) globally actuated by two DC motors. A total of fifteen human-machine connections are needed to fasten the device to the patient hand. The moving link of the thumb mechanism is actuated by a spatial RSSR mechanism whose frame link geometry must be ad hoc regulated every time the device is fitted on the patient hand. With the future goal to build a new version of the hand exoskeleton, in this dissertation three problems arising from this prototype were tackled. The first problem regards the need to lower the number of human-machine connections needed to fasten the exoskeleton to the patient hand. A new finger mechanism that permits to lower the total number of human-machine connections from fifteen to only six was proposed. The second problem regards the synthesis of the RSSR mechanism. A novel synthesis procedure was proposed in order to guarantee the optimal motion and force transmission to the thumb mechanism once the hand exoskeleton is fitted to a new patient, i.e. for different frame link geometries of the RSSR mechanism. The third problem regards the need to approximate the finger phalange motion as a rotation about a revolute axis. In this perspective, two different joint axes identification techniques were proposed. The techniques are based on the Burmester theory (a theory generally used for the synthesis of mechanisms), here used in an original way to identify an axis of rotation. A comparison of this two technique with a more standard technique based on the finite helical axis is reported.

The knee joint plays a central role in human motion for its dual function: providing a large range of motion in flexion/extension and stability in the other degrees of freedom. Computational modeling is a powerful tool to deepen our understanding of the joint mechanics, overcoming the main limitations of experimental investigations, i.e. time, cost and impracticability, and providing valuable insights for prosthetic design, rehabilitation and surgical planning. Within this background, the specific aim of this dissertation is threefold: to develop a sequentially-defined kinetostatic model of the knee, comparing the performance of spherical and anatomical surfaces; to develop a dynamic model of the knee to predict the quadriceps force during the squat activity; to estimate the compressive force that the implanted knee joint needs in order to reproduce natural stability. This dissertation presents novel and efficient procedures to model and evaluate the behavior of the natural and implanted knee under the effect of static and dynamic loading conditions, extending the current knowledge in the field of musculoskeletal computational modeling.

The knee is one of the most complex and studied joint of the musculoskeletal system provided its great importance in locomotion. Therefore, a deep understanding of its behaviour and of the role played by each of the structures composing it is fundamental. Knee joint models are an invaluable tool to understand the behaviour of the knee and their usefulness is proved in many fields such as surgical planning and prosthetic design. A huge amount of models has been proposed in the literature focusing on the kinematic, the kinetostatic and the dynamic behavior of the joint. Models can be based on in vivo or in vitro data. While the kinematic and the kinetostatic models are defined properly on in vitro data, the dynamic ones cannot. This discrepancy leads to a gap, a lack of coherence, between the usually in vitro defined kinematic and kinetostatic models and the study of the active structures of the joint. In order to achieve a comprehensive knee joint description in which the kinematic, kinetostatic and dynamic models coherently stem one from the other, the identification of a procedure that allows to obtaining reliable kinematic and kinetostatic models in vivo is needed. In the present dissertation a procedure is defined that allows for the identification of a subject specific knee joint model in vivo starting from standard clinical data obtained by the use of non invasive techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and fluoroscopy. This procedure leads to an accurate identification of the parameters needed to personalize the 5-5 parallel mechanism and its patello-femoral extension on a single patient in order to accurately reply the knee joint original motion. Furthermore, following the sequential approach to the modelling of the joint, a stiffness model of the knee is specialized on the specific subject's anatomy.

Following an attempt to harmonize the U.S. GAAP and IFRS a new IFRS standard became mandatory in the EU known as IFRS 13 “Fair value measurement” in 2013. The new accounting standard aims to decrease inconsistencies with fair value measurement by introducing new disclosure requirements for fair value assets with no active market (level 3). This study investigates how well Swedish listed firms have complied with the new disclosure requirements, and whether their compliance level has affected the information asymmetry between market participants. The sample consists of Swedish listed firms from Nasdaq OMX within the banking, forestry and real estate industry where fair value assets on level 3 are prevalent. The result revealed that Swedish firms had increased their compliance level with the disclosure requirements; furthermore, the regression analysis indicated a negative relation between an increase in disclosure level and information asymmetry after controlling for some variables. However, since the result was not significant suggestions for future research is to increase the sample size outside of the Swedish context.

<p>Within the field of immunology, the existence of autoimmune diseases presents a unique set of challenges. The immune system typically protects the host by identifying foreign pathogens and mounting an appropriate response to eliminate them. Great strides have been made in understanding how foreign pathogens are identified and responded to, leading to the development of powerful immunological tools, such as vaccines and a myriad of models used to study infectious diseases and processes. However, it is occasionally possible for host tissues themselves to be inappropriately identified as foreign, prompting an immune response that attempts to eliminate the host tissue. The immune system has processes in place, referred to as selection, designed to prevent the development of cells capable of recognizing the self as foreign. While a great deal of work has been invested in understanding these processes, many concrete answers remain elusive. </p><p>Our laboratory, which focuses on understanding the roles of E and Id proteins in lymphocyte development, has established the Id3 knockout mouse as a model of autoimmune disease. Id3 knockout mice develop a disease reminiscent of human Sj&#1255;gren's Syndrome, an autoimmune disease that progressively damages the salivary and lachrymal glands. Continued study of this model has yielded interesting results. These include the identification of CD4+ T cells as initiators of disease as well as the identification of the cytokine Interleukin 13 (IL-13) as a potential causative agent. However, the source of IL-13, its true role as a causative agent of disease, as well as the developmental basis for its elevated expression remained elusive. </p><p>To this end, I utilized a reporter gene that enabled me to detect cells producing IL-13 as well as test the effects of IL-13 deletion on disease progression. Using this system, I was able to identify both CD4+ T cells and &#947;&#948; T cells as major sources of IL-13. I was also able to determine that elimination of IL-13 in Id3 knockout mice was sufficient to block the development of disease symptoms, reinforcing the hypothesis that IL-13 is a causative agent in disease initiation. Finally, I attempted to better characterize the phenotype of cells producing IL-13. These experiments indicated that the T cell receptor (TCR) repertoire of Id3 knockout mice is markedly different than that of wild-type (WT) mice. Furthermore, cells bearing certain TCRs appeared to express IL-13 at dramatically different rates, indicating that certain TCRs may be predisposed to IL-13 particular effector fates.</p> / Dissertation